Improvement in propellers



lated taa para arpa.

JOHN D. FORD, BALTIMORE, MARYLAND.

Letters Patent No. 107,471, dated September 20, 1870.

:MiaoveM-ENT 1N PRoPnLLeRs.

The Schedule referred to in the-se Letters Patent and making part of the same.

reference being had to the accompanying drawing forming a part ofthis' specilication. .j

Thisinvention relates to improvements in screwpropellers, and consists in an arrangement for changing and securing the-blades of a propeller by apparatns worked in the vessel, so that they maybe adjusted to and secured in the position for working, or the two sets of blades may -he brought into the same axial plane for moving through the water when not revolving, so as Vto encounter less resistancev from the water than when in the working position.

Figure 1 is a side elevation i' a screw-propeller and its supports, arranged according to my improvements, and

Figure 2 is a sectional elevation of -the saine on the line x A Similar letters ot reference indicate corresponding parts.

y' A represents one pair of" blades attached to the shalt B, which works in a long sleeve, C, supported in bearings D, and carrying the other pair of propellers, E.

` 'Both the shaft and the sleeve have hubs where the blades are attached, -which-are arranged on the ends, which come in contact, to clutch together where the sleeve, which is lcapable of' end movement, is shoved outward.

This sleeve is provided with a slot, F, extending `cirel'lmferentially about a quarter of the circumferf ence, and having a Alateral notch at each end marked G and 'G'. v

H is a stop projecting from the shaft, through this slot, to arrest Vthe shaft when turning at the right point for bringing the clutches together. y

A lever, .-I, connected to the sleeve hy a ring, K, working betwcerithe collars L, and a shifting-screw, M,'are used for shifting the sleeve forward and backward, toclutch or unclutch the hubs, the said lever being provided with a fulcrum' at N, and the screwrod being provided with a nut in t-he framing or support of the sleeve.

. For shifting the blades from one position to. the

other, the sleeve is vfirst moved forward to disengage I the clutches of the hubs, and. to bring the slot 10 in vsuch relation to the pin G' as to allow the sleeve to turn on the shaft, or to allow the shaft to turn in the sleeve; the shaft is then turned to rightor left, as the l case maybe, and the sleeve is moved back again.

To prevent the sleeve front turning wit-l1 the shaft,

a screw, I, is arranged in the hearing to screw down upon the sleeve, to hold it. When the two hubs are clutched together, motion is communicated to the sleeves by the shaft through the clutches.

In the drawing the blades ofthe propeller are arranged in the sameplane as when they are not tobc revolved. The dotted lines Q, fig. 2, show the other position. The clutches are held together by the ring vK,1ever I, and rod M.

Having thus described my invention,

What I claim as new, and desire to secure by Letters Iatent, is

The combination of the -sleeve'0, provided with the slot Fand notches G G' of the shaft B, the stud H, the shifting-lever I, ring K, and the rod M, al1 substantially as specified.

^ JOHN 1).,FORD.

Witnesses:

WM. A. MiNTzEn, H. H, CLINE. 

